[R] Wrong function when import from module using get

Jakub Jankiewicz jcubic at jcubic.pl
Tue Jun 27 10:06:16 CEST 2017


I found this issue:

when I have 3 modules:

* AnalysisA
* AnalysisB
* AnalysisC

I load all modules at the beginning from list of modules:

analyses <- list('AnalysisA', 'AnalysisB', 'AnalysisC')

for (module in analyses) {
   library(module, character.only = TRUE)

and I want to add a function isValid to each module, but I've added it only
for AnalysisB. When I run this code:

# value <- <selected by user>

flags <- sapply(analyses, function(module) {
    namespace <- getNamespace(module)
        isValid <- get("isValid", namespace)
    }, error = function(e) {

# show analyses


then when R call get for AnalysisA it throw error, for AnalysisB it
return function but for AnalysisC it return function from AnalysisB and don't
throw error.

As a workaround instead of tryCatch I've used:

if ("isValid" %in% ls(namespace)) {
    isValid <- get("isValid", namespace)
} else {

Is this a bug? Should this be reported?

I'm using R 3.4.0 on windows.

Jakub Jankiewicz, Web Developer

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